Neonates are highly vulnerable to iatrogenic events due to their size, fragility, and severe sensitivity to environmental stressors. Patient safety research in neonatal intensive care units (NICU) has shown that these attributes increase care complexity and reduce the capacity of the neonates to endure even small care deviations. As a result, neonates experience adverse events at rates as high as 8 times of those reported for hospitalized adults. Adverse events are estimated to occur at a rate of 74 events per every 100 NICU patients (0-11 AE/patient), with a third being severe events. The vulnerabilities of neonates are most exposed in the perioperative environment, in which little patient safety research has been conducted. In addition to the prevailing risks to all surgical patients (e.g., misidentification, positioning errors, wrong site or side, retained foreign bodies, etc.), neonates are at increased risk to handover (e.g., NICU nurse to OR team), transport (e.g., monitoring), and intraoperative events (e.g., weight-based dosing, temperature control, etc.). The objective of this multi-site study is to improve neonatal safety by applying a novel event discovery methodology to determine the etiology of system failures in the perioperative environment. We will use the construct of the non-routine event (NRE) to more efficiently capture dysfunctional clinical microsystem attributes and potentially dangerous conditions. A NRE is defined as any event that is perceived by care providers or skilled observers as a deviation from optimal care based on the clinical situation. NREs encompass a substantially larger class of events than conventional patient safety metrics, including sentinel events, medical errors, or near misses. In prior studies, minimizing the number of deviations from standard care, minor problems, and disruptions during a case has been shown to result in smoother, safer, and shorter surgeries. Moreover, in preliminary studies by members of our team, intraoperative NREs appeared to be associated with 30-day surgical mortality and morbidity. We propose a comprehensive 4-year study of neonatal patient safety in the perioperative environment to produce the knowledge base required to inform high-impact intervention studies and guide rapid cycle quality improvement. Our Aims are to: 1a) Determine the prevalence and characteristics of NREs during the perioperative care of neonates; 1b) Delineate the relationship(s) between NREs, contributory factors, and surgical mortality and major morbidity during neonatal perioperative care; 2) Perform a comparative analysis of prospective NRE data collection with conventional event reporting methodologies within the same clinical environment; and 4) Collaborate with the Tennessee Initiative for Perinatal Quality Improvement (TIPQC) to conduct practical pilot testing of tools and measures refined in Aims 1-3. We anticipate that knowledge gained from a neonatal safety model developed from data collected prospectively at three children's hospitals and tested within the TIPQC collaborative will guide future intervention studies.